<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <!-- 到达终点数字 -->
    <script>
      var reachNumber = target => {
        target = Math.abs(target)
        let k = 0
        while (target > 0) {
          k++
          target -= k
        }
        return target % 2 == 0 ? k : k + 1 + (k % 2)
      }
      console.log(reachNumber(2))
    </script>
  </body>
</html>
